在android中繪製動畫圈

Question

我正在嘗試創建一個圓形動畫，但屏幕並未自行刷新，而是在不同位置繪製了許多圈，而不是繪製運動。我想以這種方式使用它，而不是使用invalidate()方法，因爲我想將它用於實時應用程序。

下面是代碼：

public class activity_layout_animation extends SurfaceView implements Runnable { 

    Thread thread; 
    boolean CanDraw = false; 

    Paint red_fill; 

    int circle_x, circle_y; 

    Canvas canvas; 
    SurfaceHolder surfaceHolder; 


    public activity_layout_animation(Context context){ 
     super(context); 
     surfaceHolder = getHolder(); 
     circle_x= 130; 
     circle_y=130; 
    } 
    @Override 
    public void run(){ 

     preparePaint(); 

     while(CanDraw){ 

      if (!surfaceHolder.getSurface().isValid()){ 
       continue; 
      } 

      canvas = surfaceHolder.lockCanvas(); 
      motionCircle(10); 
      canvas.drawCircle(circle_x,circle_y,50, red_fill); 
      surfaceHolder.unlockCanvasAndPost(canvas); 

     } 
    } 

    public void pause(){ 

     CanDraw = false; 

     while(true) { 
      try { 
       thread.join(); 
       break; 
      } catch (InterruptedException e) { 
       e.printStackTrace(); 
      } 
     } 

     thread = null; 
    } 

    public void resume(){ 
     CanDraw = true; 
     thread = new Thread(this); 
     thread.start(); 
    } 

    private void preparePaint(){ 
     red_fill = new Paint(); 
     red_fill.setColor(Color.RED); 
     red_fill.setStyle(Paint.Style.FILL); 
    } 

    private void motionCircle (int speed){ 

     if ((circle_y == 130) && (circle_x < 650)){ 
      circle_x = circle_x + speed; 
     } 
     if ((circle_y < 650) && (circle_x ==650)){ 
      circle_y = circle_y + speed; 
     } 
     if ((circle_y == 650) && (circle_x > 130)){ 
      circle_x = circle_x - speed; 
     } 
     if ((circle_y > 130) && (circle_x== 130)){ 
      circle_y = circle_y - speed; 
     } 
    } 


} 

謝謝！

Answer 1

postInvalidate()怎麼樣 - 你可以從後臺線程調用它。您也可以撥打canvas.drawColor(backgroundColor)從以前的圖紙中清除整個畫布。